The Usefulness of H-reflex Parameters in Patients with Mild S1 Radiculopathy

Abstract

Background: Needle EMG may be negative in mild or predominantly sensory lumbosacral radiculopathies. In such cases, an increase in the latency of the soleus H-reflex is a useful diagnostic criterion for establishing sensory fiber compromise at the S1 root level. However, if clinical signs of radicular involvement are lacking, we therefore studied the H-reflex latency and amolitude in patients with radiculopathy in order to determine if there is any evidence to support the assumption that the H-reflex parameters changes are the earlier sign and more sensitive criterion for detecting mild S1 root dysfunction than traditional NCS and EMG, Patients and Methods: Clinical and electrophysiological findings from 38 patients with back pain and radiculopathy were compared with data obtained from 40 healthy subjects. All participant underwent bilateral EMG and late response (F-wafe and H-reflex) testing Descriptive statistics, including means and standard deviations for age, H-reflex amplitudes, H-reflex latencies, side-to-side H/H and side-to-side latency differences of all participants were calculated using SPSS.Results: patients showed significant H-reflex amplitude asymmetry compared to healthy controls (p≤0.5). The H/H ratios were 0.5 in patients group and 0.8 in the healthy controls which were significantly different. Soleus H-reflex latencies, soleus side-to-side latency differences of all participants was significantly longer in patients (p≤0.5). in this study only 52.6% of the patients had EMG changes. 42.1% had prolonged F-wave latenym while 83.2% had abnormal H reflex parameters. Conclusion: The study of soleus H-reflex parameters may be usefully associated to the F0wave and needel EMG study to detect possible S1 root dysfunction in mild lumbosacral radiculopathies. The H-reflex parameters changes may be the earliest abnormality in absence of focal neurological signs.

Keywords

NCS, EMG, S1